Loma is a census-designated place in Chouteau County, Montana, United States. The population was 85 at the 2010 census. James Kipp, of the American Fur Company founded the first community here in 1831. The Blackfeet laid siege to the fort, and inhabitants quickly abandoned the site. The next year, the American Fur Company established another tradin…Loma is a census-designated place in Chouteau County, Montana, United States. The population was 85 at the 2010 census. James Kipp, of the American Fur Company founded the first community here in 1831. The Blackfeet laid siege to the fort, and inhabitants quickly abandoned the site. The next year, the American Fur Company established another trading post, Fort McKenzie, a few miles upstream of the old site. During the 1860s, businessmen built a townsite near the confluence of the Marias and the Missouri rivers, called Ophir. On May 25, 1865, the Blackfeet killed 10 men in the developing town.